Electric brake



(No Model.) 7

E. A. SPERRY. ELECTRIC-BRAKE.

No. 577,119. 1 Patented Feb. 16, 1897.

FTC-1.1. .FELZ.

' m'rsn S A ES PATEN T; OFFICE.

1 ELMER A. SPERRY; OF CLEVELAND, OIlIO, ASSIGN'OR TO THE GENERALELECTRICCOMPANY, OF NFHV' YORK.

ELECTRIC BRAKE.

SPECIFICATION; forming part of Letters Patent No. 577,119 dated February16, 1897.

Application and reirtaryis, 1895. Serial No. 539,019. iilomodei.)

To allruhom it my cancer/ Be it known that I, ELMER A. .SPERRY, acitizen of the United States, residing at Cleveland, in the county of(-Ju-yahoga andState of Ohio,- have invented certain new and usefulImprovements in Electric Brakes, of which thefoliowing is aspecification;

' The.present invention'relates to controllers j and asyste nof controlfor an-electric motor 'reqer imotors, particularly (when. used forp=ro-' pelling vehicleseither on street or other kinds of railways wherethe -motors are used for propelling the vehicle, and. when it is desiredplied to a system of to stop the motors are converted into generators,and-the ener .y thus produced is supelectric brakes' V Inrunning a carertrain it often happens thatit will, with the source of power cut off,

run on its own momentum forso|ne little time, as on a slight grade or alevel. The

power being shut off and the circuits through the motor or motors open,the magnetization 01: the field dies down, the amount remainingdepending .llPOll'jllB lCSldllitl magnetism of the pole-pieces, whichvaries according to the style of motor and the kind of iron used initsfield. It is desirable to always maintain acertain amount offieldmagnetization, so

that the motors, when converted into generators by suitable connectingdevices, may be instantly responsive to any demand for enorgy.'Espcciallyisthis the case where there arepoorcontaets between partsof.the sysjtoburn them out, and in consequence of the rhigh resistance oftheoi'rcuit the machine would build up slowly, thus taking a certaininterval of time, which, as -:\\'ill readilyibe' seen, would be aserious object-ion were it nee .essary to stop instantly on account;- ofdanger.

To overcome this objection, l wind a sepa rate field-coilon thepole-pieces of the motor,

which mayor may notform a part of the main field-winding of the motor.In this application', I from the main winding and only in circuit atcertain intervals, namely, when the power circuit is interrupted and thecontrollern main alone. tem which would require considerable energyhowever, I have shown it separate Ition the armature connections arereversed and the circuit is completed through the extra circuit fromother cont-rollers to the motor or generator is interrupted when .in theoff position. 'In the presentcase there is always a circuit between thecontroller and motor or generator. I I

In'a system as above described it has been This cell being in cirfoundthat the current generated by the motors when converted-into generatorsis too great at the start, and to take care of 'this ex cess of currentmore resistance is-inserted on the brake side than on the" power side ofthe controller, the extra resistancebeing divided into anysuitablenumber of sections and cut out step by step when the brake-cylinder isoperated. This extra resistance is idle except currenflfor thebrake-circuit flows through both main and extra resistanee,while thecur- .rent from the power system flows through the An automaticlimit-switch is provided for cutting down the current of the generatorit at any time the current flowing through the brake-circuit isexcessive, due to the fact that the motorman cuts out resistance toofast or thereby endangered. The switch consists of a magnet with ;anenergizing-coil in series when the brake-circuit.is completed. The

for'any other rcasoinand the apparatus is with the brakes, having itsarmature pivoted at the center of gravity, thereby greatly lessening thevibration due to thejolting of the 'vehicle'nnd adapted to close a pairof contacts, puttinga shunt of more or less resistance around thefield-coils of the generator;

weakening them and cansin g the current generated to be decreased. Upona predeter- 1 mined drop in the current supplied by the generator theshunt-eircuitaround the fields is automatically broken, and the switchis crane brushes are now in thef-oif? position and, unlike controllersheretofore, are in engagement with certain of the contact-plates on thebrake side of the controller; \Vith the brushes 2 2st the left of thecentral position, the ourrent will be supplied to the motor in a 1nannersuitable to propel the car, and the'circuits would be as follows: fromthe source. of cur rent 0 to the brush-'1, contact-plate 10,crossconnected to plate 11, to brush --13, through 20, to the plate 24,

. reetly to the source resistance R to brush 15, cross-connected tobrush 16, to contact 17, erossrconnected to contact 18, to brush 21,through the flexible connection 22 to the armature A of the motor,through the'fiexible lead 23 to the brush cross-connected to plate 25,to brush 26, wire 28, to field F, wire 27, to ground... By moving thebrushes farther toaiter the other of the resistance is short-circuiteduntil finally the motor is connected diof power, with noresist ance incircuit. This is indicatedin. Fig. 3.. Fig indicates the same conditionof 'circuits, except that the relation of the field and armature hasbeen reversed by means of the reversing-switch and the motor-isrotatingin the opposite direction. Assuming that the brushes are in theposition shown in'Fig. 1, the motor has been converted into agenerat-orby means of the cross connections between the plates onthe brake sigewhich are opposite to those on the power s1 6, through the armature isreversed relative to that of the field.

Assuming now that the car is running on momentum, a current will begenerated and the circuitis as follows: from the armature A tothefiexiblc lea 22, the brush 21, plate 35, cross-connectedto plate 34,through the re la, tively high'resistance field-coil f, to ground QG',thence by way of the dotted line 36 to the shunting device 5, to contact30, oross-connected to contact 29, tobrush 20, through the armature inthe direction indicated by the vdottedarrow, to the point of starting.Thus it will be seen that the shunting device. S shunts thebruke-coil Bin this position.

It will be seen from the above that the gen erator issupplying currentto the auxiliary .55. by means of the shunting device S, as shownfield-coilfand that the field F is open-circuited and that the brakecoil B isshunted irrFigs. 5 and 6, the former indicating the conditionwhen running forward, the latter back 1: ward.

Assuming so thatihe brushes rest on the line 1 1 to the and thedirection of current flowing r backward.

that the cylinder is new rotatedas follows: from the armature A, throughthe e brush 21',the'plate 3.5,-

o 27, to ground G, thence, to ground G, through the coil 'M on thelimitcross-connected to the plate 45," the brnsh'26,

wire 28, field F, wire flexible lead 22, ,to th switch, brake-coil B, tobrush B',"contact 32,

cross-connected to plate 31', to brush 31, to

resistances R R, to brush '15, by crosscon nection to brush 16, tocontact-plate 30, crosseon'nected to plate 29, brush-20, to armature A,as indicated by dotted arrow, starting. This condition of circuits corresponds to that shown in Fig.7, and. it will be noted that the auxiliaryfield ,fis short-Gin.

to point of v cuited. This is not essential to the invention,

however, for it would work as well were it open-'circuited, as shown indotted lines, and I aim to embrace that feature in the claims. Furtherrotation of the cylind'ermerely cuts out more resistance, so furtherdescription is unnecessary.- dition as above, except thatthe generatoris rotating. in the opposite direction. It will be seen by reference tothe above that the brakecircnit includes more resistance than: thepdwerside, for it includes both resistances R and R, whereas thepower-circuit only in cludes resistance R;

Referring "now the reversing-switch. is shown. 20 and 2,1 'are mountedon ing-piece, I pivoted in any suitable manner and adapted The brushes asuitable insulat- Fig. 8 indicateshthe samcon- 4 I 95 to. Fig.' 10, adetail view or to move the brushes up or down to give the requiredconnections to the armature-leads.

The armature A'is connected by flexible leads with the brushes 20 and21,whiclrare adapted to engage plates 29 and 35 .or 29 and .60, whichare mounted on a suitable cylinder or supv port. By tracing out theconnections itwill be seen thatthe current is reversed whenever thebrushes are shiftedfrom one position .to

the other. This reversing'switch is adaptedxro to shift the armatureconnections when the motor is used .to propel the car forward or subjectof my pendi ug application, Serial No.- 606,4.89, filed September 21,1806,1110 not herein make any claim to its construction.

It has been found in practical operation that in the hands of somemotormen u on applying the brake too suddenly, and it runs up to apoint-dangerous to the apparatus. In Figs. 1 and I2 is 1imlt-swltohforre- Y venting this undue increase of current, w lch shown what I term aAs this reversing-switch is-the the current is turns on i of currentrent around theiiclds throughthe resistance.

R 'and wire 42,, It IS preferable to support this armature at or aboutits center of grav- E is coupled to the motor, assh'own in Fig. 1,

ity for the purpose of reducing to a minimum the amountof vibrationwhich a lover of this .kind would be subjected .to, caused by the'jolting of the vehicle;

tion.

- Referringnowv to 9', indicates the motor-car, and 0 the trailcr.- Thecontroller and to the brake-magnets B and B in simple multiple are bymeans of wires e and-.341. '1his,'howevcr,is not the case with thebrake:

magnets 19, 13", and ll. -These are placed in multiple between the wiresand37 andiu series with an adjusting-coil J, inserted between wire a and37 and consisting of any suitable resistance, with means. for varying.

it b'y means-of which the current flowing to the group-of magnets onthe. trail-car O may-be adjust ed with reference to the group upon themotor-car C. The circuit between the brakes is a metallic one, and thereturncircuit is grounded by wire eon the axle of the motor-car.

Fig. 11 is a detail viewshowingthe eylindo! in cross-section and therclation which the'brushes hear. to the shunting devices,

This shuntingdevice 8 consists of two brushes inenntedon the back of thecontroller'in any suitable finanner, ctmnected together and adapted toengage with contact-plates and 432 when in thepo'sition shown in Fig.1.-As

soon as the cylinder is rotated in the direction of the arrow thebrushes 16 and-B,-wliich are connected to the external circuit, breakcontact with the contacts 30 and 32 and the shunting device S remainsidle, there being no eurrentin the circuit.- If the controller isrevolved in the opposite direction, one of I the brushes of the shuntingdevice S engages -.with' contact 17 and-the other brush isopencircuited. Th us it-wiil beacon that the shunt as in Fig.1..

.Whatl claim 'is-- .S is only in circuit when the controller stands '1.In an electric brake system, the eombi-' national a dynamo-electricmachine having a seriesanfl shunt fieldrcoil and adapted forpropellingnnd'breking the vehicle'mi'th means tor-maintaining afieldmnignetization at the time the dynameeleetrie machineiis not a.t-

' energizingthe fieldu iagu ets at the" time the motorie not attestingthe 'p'co puleion of the rupted;

2. an electric brake system,

footing the motion-"oi thegehiele.

g the'coinbi nation'ofa motor forpronelling-and broking the vehicle,with on auniilery'held coil' for vehicle.

a. rite cementu with sit-si nna motor,

of en auitiiiaryfield-coil, and means for auto mstieellyeonnecting thecoil in circuit with the motor when the source of supply-is inter- 4.Thecomhination of an electric motor A suitable spring and adjustingqintare provided to regulate its nohaving main and auxiliary field-coils,means for reversing the relation between the armature and fields, andmeans for connecting the auxiliary field-coil to the armature at a'timewhen the mot-or is not affecting the propulsion of the car.

5. Ina controller for clectric motors, the combination of contacts andconnections for between the-motor-circnit and, the contacts, and'afield-coil for energizing the field of the motor in'the ofif position ofthe controller. V 7. The: combination with anelectric motor, of anauxiliary field-coil of relatively high resistance, and brushes andcontacts for including the said coil in circuit with the motor-armatureat the otf positionof the controller;

combination of contacts for establishing circuit connections with themotors when propelling the vehicle,-other V-contaets for regu-- when themotors are converted into generators and supplying current to thebrakes, and means for establishing a connection between the armature andan auxiliary field-coil between the times when the power-circuit isbroken and the brake-circuit established.

9. Incombination, an electric motor, main and auxiliary field-coils,contacts and brushes for establishing connection between the main fieldand the armature of the motor, and other tween the armature and-theauxiliary fieldcoii;

vided with main and auxiliary field-coils, a

relation between armature and'field-eoils, and

' ilisry'field-coil in circuit with the armature.

machine having an auxiliary field-coil, of

circuit, brushes for establishing connection.

Listing the supply of current to the'br'akes 10.. in combination, anelectric inotorprm controller for regulating'the current flowing throughthe motor, means for reversingthe' contacts and brushes for connectingthe auxi means for disconnecting eitherone orthe regul'ating-t-he supplyof energy to the power I t 8. In acontroller for electric motors, the

contacts for establishing circuit relation be 11. In an electric-brakesystem, the coalbination of." means for placing the motor in operativeconneetion with aIsource-ot electtrieel supply so as to be driven. as amom; mans for reversing the relation of the arms tnrcnnd held of themotor and operatively connecting the armature-circuit toan' euxiliary'field coil or coilson the motonan'd means for coupling the armature to alowresistance 12. The combination, with ascries electric I other of suchfield-coils from tho armaturecircuit, and a revcrsing witch for thearmature-circuit. '13. The combination, with aserios electric 5'rnachine having an auxiliary field-coil, of me'ansfor disconnectingeither one or the other of such field-coils from the armaturecircuit, areversing-switch for the armaturecireuit, a plurality of exteriorcircuits, and

Q means for coupling them successively to the said motor. a

14. In an electric controller, the combination of a plurality ofcircuits, certain of which i f ,are iior regulating the current suppliedto the -i5 motors, certain others for regulating the energy supplied tothe brakes,- resistance ineluded in the first-named circuit, and thesaid resistance plus other resistaneeinc'luded in the brake-circuiin 15.The combination of I a dynamo'electric a machine forpropellingahdrbraking purposes,

means for including the machine in circuit with the source of supplywhen it is desired forpropclling 'purposc's,, and for disconnect g5 ingit from the supply and converting itinto a generator for brakingpurposes, and an automatic switch for closing and opening ashunt-circuit around the field-boils of the d ynamo-electric machinewhen acting as a gen- 3o orator for preventing an increase of current*overja predetermined amount.

16. The combination of a dynamo-electric machine mounted-on a vehiclefor propelling .and braking purposes, a controller. for Iin-;

5 cluding the machine in circuitwith the sourcev q of supply andregulating the energy suppliedthereto, and for disconnecting the machinefrom the supply, converting it intoa generator and regulating the energysupplied thereby to the brake-.circuigand an automatic device forshunting .a part'oi' the current around the machine when it is acting asa generator; .7 ,7 17, The combination of a dynamo-electric machineforpropelling and braking purposes, a controller for regulating themachine when employed-for'propellihg and braking ,7 purposes, and-anautomatic switch controlled by the current in the brake-eircuit forclos-5o ing a shunt around the field-coils of the ma chine when it is actingas a generator. 1 18. The combination of an electric motor,

a controllerprovided with means for converting-itinto a generator, anauxiliaryfie'ldcoil, means for establishing connection be-' tween thefield-coil and the armature, and an automatic shunting device for thegenerator. 19. In combination with a series electric motor,a'plurality'of exterior circuits, means for changing the circuitconnection of said.

motor from one to the other of the said exterioncireuits, a device forconverting the motor into a generator, operated by such means, --andmeans for automatically weaken '1 ing the field magnetization of thegenerator --without directly-altering thelcurrent in' the armature, saidmeans-responsive to current produced by the generator'when such currentrises -or tends to rise above a predetermined amount. a l 20. .Incombination with a series electric motor, a plurality of exteriorcircuits, means.

for changing the circuit connection of the said motor from one to theother of the said exterior ei rcuits, a device for converting the motorinto a generator operated by such means, and an automatic shunt-for thefield magnet res'pousiveto the current in one of said ex .teriorcircuits.

21. The combination of an electric motor,

a controller for regulating the same a plurality of circuits extendingtherefrom, more resistance-included in one circuit than in the others,main and auxiliary field-coils for the motor, and means forconnectingthem in any desired relation with the armature.

.22. The combination of. a series-wound dynamo-electric machine forpropelling and braking purposes, means for including it in coilof'suchgenerator, the said shunt-being circuit with the source of supplywhen it is desired to propel the vehicle, and for discon meeting it fromthe supply and converting it into a-generator, and an antomaticlimit-"jswitch for shunting the same when it is used for braking.

23. The combination of a vehicle, a dyna'mo- I electric machineforpropelling and braking purposes mounted thereon, meansfor includ ing themachine in circuit with the source of supply when employed for drivingthe load and for disconnecting it from the supply and convert-in g itintoa generator for brakingpur- (glulating the braking energy poses, andfor re and automatic means eonwhen so 'connecte trolled by the currentin the brake-circuit for preventing the locking of the vehicle-wheels bymeans of the brake-magnets.

24. The combination of a dynamo-electric machine for propelling andbraking a vehicle,

with means for maintaining a field magnetiza tion at all times when thevehicle is in motion.

25. The combination in an electric-brake system, of brakes on themotor-car connected iiiparallel, brakes on the trailer-connected in agroup, and'a resistance for regulating the supply of energy to thegroup.

w 26. The combination in an electric-brake system; of brakes on themotor-car connected in parallel, brakes on the traileneonneeted in agroup, the members of the group eonneeted in parallel with each other,and the group as a whole connected in series with the source of supply.

27; In-an electric-railway system, the corn bination of means forplacingzthe moter'm around the brakes, and means for'simultaneouslycoupling the armature-circuit with a' low-resistance field-coil andopening said shunt. 4 t 28. In an electric-brake system, the c0mbinaticnof a-dynamo-electric' machine for propelling aud'braking the car;acontroller provided. with contacts and brushes for establishing desiredcircuit relations,;and a shuntxo ing device for the brake-magnets. 29.'In an eleetric brak'e system, the eo1 n-' bination of, a.dynamo-electric machine for ti me.

propelling and braking the car, acentroller provided with contacts andbrushes for establishing connections between the dynamo-electric machineand the brake-magnet coils, and

a mechanical shunting device for shunting the brake-magnet eeils at apredetermined.

